Throw-out and belt tensioning mechanism for power lawn mowers



Feb. 18, 1941. w LQDER 2,232,671

THROW-OUT AND BELTTENSIONING MECHANISM FOR POWER LAWN MOWERS Filed March 23, 1939 2 Sheets-Sheet 1 I NVENT OR.

BY 1%?? /Lazmp ATTORNEY.

Feb. 18, 1941. w LQDER 2,232,671

THROW-OUT AND BELT TENSIONING MECHANISM FOR POWER LAWN MOWERS Filed March 23. 1939 2 Sheets-Sheet 2 1N VENTOR.

s5 BYHUWHAZQLJDEH ATTORNEY.

Patented Feb. 18, 1941 UNITED STATES 'rnnJow-ou'r am) new msromo MECHANISM roa rowan LAWN MOWEBS Howard W. Loder, Montclair, N. 1., amino: to

Whiriwin d Lawn Mower Corporation, a oorpo ration of Louisiana Application March 23, 1939, Serial no. 263,827 6 Claim (01. sis-25.4)

This invention relates to new and useful improvements in power lawn mowers of the type employing horizontal rotatable cutters, in which the power drive to the cutter is belt operated.

In the operation of lawn mowers, it is many times necessary to move from one plot of ground on which cutting is being done to another. Under such conditions, it is most desirable to be able to propel the mower under its own power. In the mowers of the rotary blade type heretofore in use, operation of the propelling drive mechanism also resulted in operation of the cutter housing transmission. With the cutter arm thus revolving the cutting arm and blades can be damaged through contact with sticks, stones or other obstructions which are particularly present on gravel roadways or paths over which in such instances the mower is many times propelled. Again, such mowers, because of their adaptability, are manytimes used to clean out extremely high and thick stands of grass in which refuse and obstructions of various kinds are present and which the mower operator fails to discover until the cutter arm and blades come in contact therewith. It is obvious that only prompt and immediate withdrawal from such contact or in the alternative, means for stopping the rotation of the cutting arm and blades can prevent serious damage to the mower.

It is an object of my invention to provide a simple and efilcient means of engaging or disengaging the cutter housing transmission at the election of the operator, without in any way interfering with the continued operation of the motor which also provides propulsion for the mower.

Another object of this invention is to provide an equalized tension on the belt of the cutter housing transmission when .it is in operation. with the belts generally used, slippage incident to wear and stretch of such belts has heretofore imposed a penalty of inefficiency in the operation of the drive.

With these and other objects in mind, this invention may consist of certain novel features of construction which will be best understood from the following description-read in light of the ac- Figure 5 is a front elevation of my invention in its disengaged position;

Figure 6 is a view taken on the line 8-6 of F e 5;

Figure 7 is a front elevation of my invention in 5 its engaged position; and

Figure 8 is a view taken on the lines 8 -8 of Figure 7.

It is to be understood that my invention is not to be limited by the exact embodiment of the device shown, which is merely by way of illustration and not limitation, as various other forms of the devices may be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the appended claims.

In the accompanying drawings, the numeral l0 designates the conventional inflexible housing with a top wall H, side walls 12 and a rear wall I3 pivotally secured and extending downwardly at an obtuse angle which permits any cut material to easily clear from the under part of the mower. The top, side and rear walls of the housing are substantially free of any openings and thus define a confined air space open only to the ground and the forward end of the housing.

' The housing is mountedon front and rear pneumatic wheels. The front wheels l5 are suitably rotatably mounted on stub axles II, which are threaded and locked in angles l8 on the underside of the top and side walls II and I2.

A through transverse axle IS with proper bearings suitably secured, is enclosed in an axle housing 20, which is attached as at 2! by U-bolts 22 to the underside of the top wall I I.

Spaced away from, but adjacent to, the side wall l2, on the axle i9, is a conventional differential 25 comprising coverplates, bevel and pinion gears and a spider. Secured between the spider and the inner cover plate is a sprocket 26. The hub of one of the beveled gears is locked in the bore of a wheel hub of one of the rear pneumatic wheels it, which in turn acts as the outer cover plate of the differential.

Mounted on the top wall ii of the housing It medially between the side walls l2 and over the axle housing 20 is a motor 21. To the front and right of the motor a speed reducer 28 is mounted, on' the input shaft of which is looked a double groove, V'-beltpulley 30, and on the output shaft of which is suitably secured a twin disc clutch 32,1, 50 the facings 33 of which are engageable with a sprocket 34. Th? sprocket 34 is in alignment with the sprocket 26 and connected therewith by a suit- I able endless chain 36. The motor shaft carries a double groove V-belt pulley 38, which is aligned 55 with the v-beit pulley SI of the speed reducer ll. 'lherespectivev-beltpulleysllandllaresodesigned that regardleofwhlchsetof complementarygroovesareinuaaaV-beltilofalength olutionsperminutethataretakenbythespeedreducer input shaftaothatasubstantial variation in speedmayhe obtalne'd by using either one set ofgroovesortheother. Ailatbeltpulleyllisalso keyed to the outer end of the motor shaft and interposedbetweentheflatbeltpulleyllandthev-belt pulley 38 is a keyed circular flat belt pulley guard II. which is also carried by the motor shaft. The purpose of both the iiatbelt pulley II and the guard II will hereafter more fully appear.

Securely fastened on opposite sides of the motor are handle brackets ll slotted so as to permit adjustment of the angle at which the handles 42 are projected upwardly and rearwardly from the mower housing II. The handles are braced against lateral displacement by the tubular member ll. Clutch operating mechanism consisting of a handle member 44 pivotally secured to the mower handle as at II, a tie rod 4., adjustable as to length, secured as at 41, to the handle ll, linkage 40 secured to the lower end of the tie rod 48, and an open end U-shaped member ll, slotted to fit the studs ll of the clutch collar II, and secured to the lower endof linkage ll, permits an operator to easily engage or disengage the clutch facings 33 with the driving sprocket 34. with the motor 21 operating, engagement of the clutch facings II with the sprocket 34 transmits propelling power to the driven sprocket It and hence to the axle l8 and its wheels I. The tie rod ll adjustment is afforded so that change of the angle at which the handles 42 project from the mower housing ill will be permissible without disrupting the linkage ll or its pivotal connection with the U-shaped member u.

Within the housing It is a horizontally disposed rotatable cutter arm 52, to the ends of which cutter blades 53 are appropriately seem-ed. The cutter arm is mounted to the lower end of a removable cutter shaft ll, which extends upwardly through a complementary sleeve 55. which in turn is supported for rotation in bearings within a cylindrical bearing housing 5|, the upper end of which extends through an opening 51 in the top wall of the housing ill, and has a flange it resting upon and secured to this top wall.

The shaft II is provided with a left hand thread at its lower extremity and a right hand thread at its upper end. Spacers 50 bored to the diameter of the shaft are removable therefrom. By removing one or more of the spacers from the shaft in the position in which they are shown in Figure 3, and placing them on the shaft adjacent the cutter arm between the cutter arm and the lower periphery of the sleeve 55, the height at which the cutter arm may be operated can be adjusted within the range afforded by the width of the spacers. with the spacers in place, the length of the shaft 54 is such that by tightening either or both of the nuts N or I, the shaft is locked against rotation in the sleeve 55.

Spaced on opposite edgesof the flange II are bosses 62. The bosses are threaded as at 63 and carry a U-shaped frame 64, which is pivotally movable in and out of a horizontal plane, and is secured by threaded hardened bolts 65. The closed end of the U-frame 64 extends toward the forward end of the mower. The arms 04' of the U-frame arebored adjacenttheirendsandcarryashaft. Two identical idler pulleys II are supported for rotation on bearings carried by the shaft 08.

The sleeve II is shouldered as at II and has keyed to its outer periphery above the shoulder a flat belt pulley ll. A flat belt ll isplaced in operable contact with the cutter sleeve pulley ll, the idler pulleys 61 and the flat belt motor pulley llasisbestdisclosedbyl'lguresfiandB.

Securedtothefla'ngellasat 1|,toinnoway interfere with the pivotal play of the U-shaped frame N, is an angle member I! bored as at It.

A A headed shaft ll isseated in the bore 13. Interposed between the head of the shaft 14 and the member I! in a freely pivotal relationship is a link It. A stud 16 of a length sufficient to extend under the bottom periphery of the U-shaped frame 84 adjacent the member 12, is secured to one end oftheiink llandassolocatedismedialofthe forward end of the U-shaped frame. To the other end of the link It, as at 11, is secured one tail of a tension spring II. The other tail of the spring I! is secured as at I. to a threaded bolt ll adjustably held by its complementary nuts II to an ear I! of a member If.

The member I! is pivotally secured as at I to one end of an arm 88, which is secured at its other end to a rod N. A hearing for the rod .3 is afforded by the bore 81 in the upturned flange I! of a member 0!, which rests on the wall II and is suitably fastened thereto. The rod II extends rearwardly along the top of the wall H and is maintained in its parallel relationship through the medium of an additional bearing afforded by a bore 00 in the upturned flange SI of a member 92, which also rests on and is fastened to the wall II. The extension of the rod 86 is continued to substantially the rear edge of the wall II at which point a universal joint 0 is interposed. The rod is then extended parallel along the length of the handle 42 and held in such relationship by a bearing aiforded by the bore ll of a flange OI of a member 98. A handle 91 is secured at right angles to the rod 06 as at 98, and is adjustable as'to its position on the rod 86 by a set screw ll.

The operator of a mower to which my invention is applied may, by placing the handle I of the rod 86 in the position shown in Figures 4 and 5, disengage the flat belt I0 from operable contact with its complementary pulleys ll, '1 and N and the rotatable cutter arm I! comes to a complete stop. The belt disengagement action is transmitted through the universal joint II to the arm and link and II, so that the forward end of the U-shaped frame 64 is freed from the support of thestud l6 and the action of a spring m secured as at II and I02 effects a positive release of the idler pulleys 61 from any engagement with the flat belt I0, which in turn frees the belt from operable contact with the pulleys 40 and 69.

As the belt Ill is released from engagement with the pulleys II, the belt slack thus created tends to throw the belt outwardly and rearwardly toward that portion of the arms 64 of the U-shaped frame 64, which extend toward the motor 21 and toward the guard 40'. To assure retention of the belt within the limits deilned by the arms 84' left and right belt'guards Ill! and I are secured to the sides of the arms 64' of the U-shaped frame 64 by being interposed between the arms and the retaining nuts 66' of the shaft It. In addition, a belt-retaining arm I0! is also interposed between one of the arms and the retaining nut 88' of the shaft l and as secured extends through the slot of the guard I" in such position that the back of the belt will come in contact therewith as the belt is urged outwardly and rearwardly as is best shown in Figure 6. This contact is suincient to hold the belt free of the pulley" l0 and the continued rotation of that pulley will not damage the belt. At the same time, the contact is such that as the handle 91 is placed in the position shown in Figure 7, the belt will release readily without damage or wear to its outer casing. The provision of the guard ll in turn prevents the belt from being displaced from the pulley 40 in a rearward direction-l To obtain operable contact between the flat belt 10 and the pulleys 40, O1 and 69, the operator turns the handle 91 to the position shown in Figure 7. The stud I! then raises the forward end of the U-shaped frame 84 sufiiciently to place the idler pulleys 61 in engagement with the belt and the consequent transmission of power to the cutter arm 52 rotates it at cutting speed.

Any normal stretch or wear in the flat belt III is compensated for by the tension of the spring 18, which in its extended position, as shown in Figure 7, exerts a constant pressure on the fiat belt. This pressure maintains the proper flat belt tension, prevents belt slippage, and also overcomes any contrary action of the spring I00. Bhould'abnormal wear or belt stretch occur, the same may be compensated for by tightening the threaded bolt 80, which changes the angle of the link II so that the stud I6 is permitted to engage the lower periphery of the U-shaped frame 64 through V a longer path of effective travel and consequently the same relative tension of the spring 18 is maintained.

What I claim as my invention is:

1. In a mower of the character described, a wheel supported housing, a mower handle secured to said housing, a motor mounted on the housing, a pulley keyed to the crank shaft of said motor, a transmission housing mounted on said first mentioned housing, a U-shaped frame pivotally secured to said transmission housing in a plane above both of said housings, rotatable means adjacent the open end of said U-shaped frame, rotatable means carried by said transmission housing, a fiat belt, said flat belt, transmission carried rotatable means, U-shaped frame carried rotatable means and pulley co-acting to eifect rotation of a cutting element within said first mentioned housing and} means manually operable from said handle to eflect a change in the position of said U-shaped frame whereby said co-action between said elements ceases.

2. In a power mower, a wheel supporting housing having top, side and rear walls defining a confined air space open to the ground, a mower handle adjustably secured to said housing, a motor mounted on the housing, means connected to the motor to propel the mower, a pulley keyed to the crank shaft of said motor, a transmission housing mounted on said first mentioned housing, means rotatably carried by said transmission housing and extended into said air space, a pulley mounted on said rotatable means above the top wall of said first mentioned housing. a U-shaped frame pivotally secured to said transmission housing in a plane above both of said housings, idler pulleys secured adjacent the open end of said U-shaped frame, a fiat belt engageable with all said p'ulleys, means which in one position co-acting with said U-shaped frame engage the fiat belt with said pulleys under a maining having top, side and rear walls defining a confined air space open to the groimd, a mower handle mountedto said housing, a power source mounted on the housing, means connected to the power source to propel the mower, means to disengage the propelling means and power source, a pulley keyed to the crank shaft of said power source, a transmission housing mounted on said first mentioned housing, a sleeve rotatably secured in said transmission housing and extended into said air space, a shaft secured against rotation within said sleeve and also extended into said air space, a second pulley mounted on said sleeve, idler pulleys shaft carried by a U-shaped frame pivotallydnterposed between said first and second mentioned pulleys and in a plane above said housing, a fiat belt engaging said first and second mentioned pulleys and said idler pulleys, a bell crank positioned to hold said U-shaped frame in a substantially horizontal plane over said housings whereby a predetermined tension is maintained on said belt and a cutter carried by said shaft is rotated within said air space, and linkage manually operable from said mower handle to change the position of said bell crank and the plane of said U-shaped frame whereby operable engagement between said flat belt and said pulleys cease.

4. In a power mower, a wheel supported housing having top, side and rear walls defining a confined air space opem to the ground, a mower handle mounted to said housing, a motor mounted on the housing, means connected to the motor to propel the mower, a pulley keyed to the crank shaft of said motor, a transmission housing mounted on said first mentioned housing, means rotatably carried by said transmission housing and extended into said air space, a cutter in a horizontal plane within said air space secured to the rotatable means of said transmission housing, a pulley mounted on the rotatable means of said transmission housing above the top wall of said first mentioned housing, a U-shaped frame pivotally secured to said transmission housing in a plane above both of said housings, idler pulleys secured adjacent the open end of said U-shaped frame, a flat belt engageable with all said pulleys, a bell crank which in one position co-acting with said U-shaped frame engages the fiat belt with said pulleys under a pre-determined tension whereby said cutter is rotated within said air space and which in another position permits disengagement of said pulleys from operable contact with said belt whereby rotation of said cutter ceases, and linkage manually controlled from said mower handle to affect selection of said bell crank positions without affecting the operable relationship of said propelling means and motor.

5. In a power mower, a wheel supported housing having top, side and rear walls defining a confined air space open to the ground, a mower handle mounted to said housing, a power source mounted on said housing, a pulley keyed to the crank shaft of said power source, a transmission housing mounted on said first mentioned housing, means rotatably carried by said transmission housing and extended into said air space, a pulley mounted on said rotatable means above the top wall of said first mentioned housing, a U-shaped frame pivotally secured to said transmission housing in a plane above both of said housings, idler pulleys secured adjacent one end of said U-shaped frame, a fiat belt engageable with all of said pulleys, a crank mounted on said first mentione'd housing which in one position co-acting with said U-shaped frame engages the flat belt with said pulleys under a predetermined tension whereby said cutter is rotated within said air space and which in another position permits disengagement of said pulleys from operable contact with said belt whereby rotation of said cutter ceases, and linkage mounted on said first mentioned housing and said handle and manually controlled from said handle to affect selection of said crank positions.

6. In a power mower, a wheel supported housing having top, side and rear walls defining a confined air space open to the ground, a mower handle mounted to said housing, a power source mounted on said housing, means connected to the power source to propel the mower, means to of said housings, idler pulleys secured adjacenflilo one end of said U-shaped frame. a fiat belt engageable with all of said pulleys, a crank mounted on said first mentioned housing which in one position co-acting with said U-shaped frame en'- gages the fiat belt with said pulleys under a predetermined tension whereby said cutter is rotated within said air space and which in another position permits disengagement of said pulleys from operable contact with said belt whereby rotation of said cutterceases, and linkage mounted on said first mentioned housing and said handle and manually controlled from said handle to affect selection of said crank positions without afiecting the operable relation of said propelling means and motor.

HOWARD W. LODER. 

